MX2010004778A

MX2010004778A - Arm blank and method of manufacturing same.

Info

Publication number: MX2010004778A
Application number: MX2010004778A
Authority: MX
Inventors: Naoaki Shimada; Michitaka Yoshida
Original assignee: Sumitomo Metal Ind
Priority date: 2008-11-12
Filing date: 2009-10-19
Publication date: 2012-09-28
Also published as: EA201400243A1; WO2010055747A1; KR20140131574A; CA2699723A1; KR20100074236A; AU2009308522B2; CN101903198A; US8776567B2; BRPI0905364A2; ES2435245T3; AU2009308522A1; JPWO2010055747A1; PL2345549T3; EP2345549B1; CA2699723C; US20120247170A1; ZA201002752B; US20100276902A1; EA024298B1; KR20130097816A

Abstract

An arm blank for an upper arm and a lower arm for forming a double wishbone suspension device of an automobile, the arm blank having a flat hollow closed cross-sectional shape, reduced in size and weight, and having increased strength. An arm blank adapted for a suspension device of an automobile and having a body consisting of a metal member.Â The metal member has a flat hollow closed cross-sectional shape having a pair of long sides arranged so as to face each other, and the metal member is formed integrally in the longitudinal direction thereof.Â The body has a first curved section curved in a plane substantially parallel to the pair of long sides.

Description

ARM MATERIAL AND A METHOD FOR ITS MANUFACTURE Technical Field This invention relates to an arm material and a method for its manufacture. Specifically, this invention relates to a upper arm material and a lower arm material, which are structural elements of a double wishbone suspension or a multiple rod suspension for a car and which has a light weight, a small size, High strength, high production and low cost due to a flat cross-sectional shape. The present invention also relates to a method for its manufacture.

Technology Background In recent years, fork suspensions and MacPherson strut suspensions have been widely used as car suspensions. Between the fork suspensions, a double fork suspension supports the rim and a tire through a rod mechanism having a parallelogram shape constituted by an upper arm and a lower arm. With a double fork suspension, when the wheel moves up and down due to the contribution of the road surface, the pivot tilt and the cant angle that does not deflect easily, makes it easy to stably maintain the contact area between the tire and the road surface. A multiple rod suspension that is a variation on a double wishbone suspension is also used a lot as a suspension for automobiles.

An arm material for an upper arm (also referred to as the upper control arm) and a lower arm, which are structural components of a double fork suspension and a multiple rod suspension (collectively referred to herein as "double fork suspension"), have been manufactured through Weld the formed parts by press working a steel sheet, through drilling a thick plate, through forged aluminum alloy and similar methods.

In recent years, the decrease in the weight of automobiles has been promoted as a counter measure against global warming. A double wishbone suspension tends to become longer in structure than a MacPherson strut suspension, so its weight tends to increase. For this reason, there is a great demand for additional decreases in weight, decrease in size, increase in strength and decrease in cost of structural parts such as the upper arms and the lower arms of double fork suspensions.

Patent Document 1 discloses an invention pertaining to a fork suspension having an upper arm that is formed in the shape of an "A" through bending a simple metal sheet and having an upper portion, an inner flange and an outer flange. A ball joint support portion is provided as an outer end in the width direction of the vehicle body in the upper arm portion. A bushing support portion is provided at the inner end of the widthwise direction of the vehicle body on the inner flange. The inner flange and the outer flange are formed such that on the outer side of the vehicle body width direction, the length in the vertical direction of the outer flange is longer than the length in the vertical direction of the flange inside. Additionally, the inner flange and the outer flange are formed such that on the inner side in the widthwise direction of the vehicle body, the length in the vertical direction of the inner flange is longer than the length in the vertical direction of the outer flange. This invention can reduce the weight and increase the rigidity of a higher arm.

That upper arm is manufactured by folding a base material comprising a single sheet of metal in the form of an "A". Therefore, manufacturing costs are necessarily high and there is inevitably a bending limit. This makes it difficult to make the form that is ideal from the performance point of view, and the production is bad. Additionally, there are demands to further increase the strength of this type of upper arms.

Patent Document 2 discloses an arm for a suspension having a structure of double tubes in the place that the resistance is required. According to the invention, a suspension arm is manufactured by adjusting a reinforcing tube element in places that require strength and tracing, hydro-forming and press forming to obtain the final shape. The manufacturing method requires complicated work steps, so that the production of a product is bad and costs are difficult to reduce. Additionally, it has the problem that resistance is markedly diminished in places where it is not reinforced.

In Patent Document 3, the present applicant discloses an invention that relates to a flexing apparatus. Figure 3 is a schematic explanatory view showing that flexure apparatus 0. In that invention, as shown in Figure 3, a product formed by bending (a bent product) is manufactured using a bending method in which a tube of metal Or a metal rod (collectively referred to below as a metal tube) 1 which is supported by a support element 2 so that it can move in its axial direction undergoing bending of the flow side down the support means 2 while being fed from the flow side up to the flow side down by a feed device 3.

Specifically, a high-frequency heating coil 5 quickly locally heats the metal tube 1 on the downstream side of the support element 2 at a temperature at which quenching is possible. On the downstream side of the high frequency heating coil 5, a cooling device with water 6 rapidly cools the metal tube 1 heated. A movable roller die 4 has at least one pair of rollers 4a that can support the metal tube 1 as if it were powered. The movable roller die 4 imparts a bending moment to the portion of the metal tube 1 which was heated to a high temperature by moving two-dimensionally or three-dimensionally on the downstream side of the cooling device 6, thereby performing the bending of the tube. metal 1. According to this invention, a bending product can be manufactured with high operational efficiency while achieving the desired working precision.

Previous Technology Documents Patent Documents Patent Document 1: JP2004-291963 to Patent Document 2: JP 10-166823 A Patent Document 3: WO 2006/93006 Disclosure of the Invention Problem that will be solved by the invention With the upper arms and manufacturing methods an arm disclosed in Patent Documents 1 and 2, it was extremely difficult to achieve light weight, small size, high strength, high production and low cost. In particular, these manufacturing methods have a plurality of steps, so that manufacturing is time consuming, manufacturing costs are high and production is poor.

The flexure apparatus disclosed in Patent Document 3 is based on the use of a metal tube having a round cross-section as a base material. If it is a question of manufacturing an upper arm of a double fork suspension using that bending apparatus, it is necessary to use a base material made of metal having a flat cross section including at least a pair of long sides and to perform the bending in a plane including one of the long sides to make the folded product that bends in a plane approximately parallel to the pair of long sides.

However, in that bending process, the base material made by metal having a flat cross section is bent in a direction that has an extremely large resistance to deformation. Therefore, the distortion or rupture of the base material can occur during bending. For this reason, no studies have been carried out on the manufacture of an upper arm and a lower arm using this method of bending.

The object of the present invention is to further decrease the weight, decrease the size, increase the strength, increase the production and decrease the cost of an upper arm and a lower arm of a double fork suspension for a car.

Means to solve the problem The present inventors conducted diligent investigations on the bending apparatus disclosed in Patent Document 3. They found that it is an extremely uncommon bending apparatus because it has the ability to easily and reliably form a bent product having a complicated shape that was not thought of. to be possible according to the technical common sense of the people with experience in technology. As a result of further studies, the present inventors found that through the use of the flexure apparatus, it is possible to provide an arm material that allows to further decrease the weight, decrease the size, increase the strength, increase the production and reduce the costs. As a result, the present invention ends.

The present invention is an arm material and more specifically, an upper arm material or a lower arm material for a car suspension, the arm material has a body comprising material from parts made of metal. The material of the fabricated parts of metal has a flat, hollow shape, with a closed cross section having a pair of opposite long sides and is formed in a single element in its longitudinal direction. The body has at least a first bent portion that is bent in an approximately parallel plane of the pair of long sides.

From another point of view, the present invention is a method of manufacturing the above-described arm material according to the present invention through (a) supporting the material of the fabricated parts of metal having a flat, hollow shape cross-section closed in a first portion while being fed relatively in its longitudinal direction, (b) locally heating the material of the parts made by metal that are fed to a second position downstream of the first position in the feed direction of the material of the fabricated parts of metal, (c) in a third position downstream from the second position in the feed direction of the material of the metal fabricated parts, cooling the portion of the material of the manufactured parts of metal that were heated in the second position, and (d) impart a moment of flexion to the heated Proción of the material of the parts manufactured by metal to tr before supporting the material of the fabricated parts of metal through a support element in a region downstream of the third position in the feeding direction of the material of the parts fabricated by metal while varying the position of the two-dimensional support element or three-dimensionally at least in a plane approximately parallel to the pair of long sides in the region.

In the present invention, the body preferably has at least a first portion and a second portion in its longitudinal direction and a second portion between the first portion and the second portion so that a pair of long sides in the first portion and a pair of long sides in the second portion are in different planes between them.

In the present invention, installation holes or the like for a ball joint support portion or a hub hub installation portion can be provided in the arm material to obtain an upper arm or a lower arm as a final product .

Effects of the Invention According to the present invention, an arm material is provided which is an element of a double fork suspension for a car. This arm material has a flat, hollow shape, with closed cross section and therefore can achieve a further decrease in weight, decrease in size, increase in strength, increase in production and decrease in cost.

Brief explanation of the drawings Figure 1 is an explanatory view showing the simplified and schematic form of an example of the structure of an upper arm of a double fork suspension according to the present invention.

Figure 2 is an explanatory view schematically showing an example of a method of manufacturing an arm material according to the present invention.

Figure 2 is a schematic explanatory view showing an example of the method of manufacturing an arm material according to the present invention.

Figure 3 is a schematic explanatory view showing a flexure apparatus according to the invention disclosed in Patent Document 3 through the present applicant.

List of reference numbers in the drawings; 1: material made of metal, 1-1: parts material made of metal 2: support element 3: feeding device 4a: pair of rollers, 4: mobile roller die (movable support element) 5: high frequency heating coil 6: cooling device with water 10: double fork suspension 11: arm material lia: body of the arm material 12, 13: long sides 14: closed cross section shape 15: surface 16: first portion bent 17: first portion 18: second portion 19: second bent portion Modes for carrying out the invention Next, the best ways to carry out the present invention in detail are explained while referring to the attached drawings. . In the following explanation, an example will be given of the case in which the arm material according to the present invention is a upper arm material for a double fork suspension. However, the present invention is not limited to this mode, and can similarly be applied to a upper arm material for a multi-rod suspension and can also be applied to a lower arm material. [Arm material] Figure 1 is an explanatory view showing in simplified and schematic form an example of the structure of an arm material 11 of a double wishbone suspension 10 according to the present invention.

As shown in this figure, this arm material 11 has a body Ia formed of a material of parts made of metal. The body lia is formed of a single element in the longitudinal direction. The body lia is also formed of a single element in the circumferential direction in a cross section. However, the present invention is not limited to this structure and the body may have one or more joints (such as welds) in a circumferential direction.

The body has a flat, hollow, closed cross-sectional shape 14 over its entire length. The closed cross-sectional shape 14 has a pair of opposed long sides 12 and 13. The body Ia has a first bent portion 16 in a plane 15 that is approximately parallel to the pair of long sides 12 and 13. The first bent portion 16 is bent two-dimensionally.

As shown by the single-dash chain line in Figure 1, the body has at least a first portion 17 and a second portion 18 in the longitudinal direction.

The body has a second bent portion 19 between the first portion 17 and the second portion 18. With this structure, the body a has a shape deformed so that the pair of long sides 12 and 13 in the first portion 17 and the pair of long sides 12 and 13 in the second portion 18 are in different planes from each other.

The body of the arm material may have two or more bent portions 16. Similarly, the body of the arm material may have two or more bent portions 19.

Next, a method of manufacturing this arm material 11 will be explained.

[Manufacturing Method] Figure 2 is a schematic explanatory view showing an example of the method of manufacturing this arm material 11.

As shown in Figure 2, a long part material made of metal 1-1 is used as a base material. The material of the long parts made of metal 1-1 has a flat, hollow shape, with closed cross section 14.

A feeding device 3 feeds the material of the parts made of metal 1-1 in its longitudinal direction. An example of the feeding device 3 is one that uses an electric servo cylinder. An example of the feeding device 3 need not be restricted to a specific type of feeding device. For example, a feeding device known as one that uses a ball screw or one that uses a band or time chain can be used as a feeding device.

The material of the parts made of metal 1-1 is fed at a predetermined speed in its longitudinal direction (the axial direction) by the feeding device 3, while being held by a holding portion 7.

A support element 2 supports the material of the parts made of metal 1-1 in a first position A. The support element 2 supports the material of the parts made of metal 1-1 which is fed in its axial direction by a device 3 in the first position A so that the material of the parts made of metal 1-1 can move. By way of example, a pair of opposed non-driven rollers can be used as a support element 2. The support element 2 need not be limited to a specific type, and it is possible to use another conventional support element as a support device. In this way, the material of the parts made of metal 1-1 passes the installation position A of the support element 2 and is fed in its longitudinal direction.

A second position B flows down from the first position A in the feed direction of the material of the parts made of metal 1-1, a high-frequency heating device 5 locally heats the material of the parts made of metal 1-1 which It is feeding.

A device having a coil that can perform a high frequency induction heating of the material of the parts made of metal 1-1 can be used as the high frequency heating device 5. The high frequency heating device 5 can be a conventional high-frequency heating device of this type.

The distance of the heating coil of the high-frequency heating device 5 from the material of the parts made of metal 1-1 in a direction parallel to a direction perpendicular to the axial direction of the material of the parts made of metal 1-1 may vary for performing non-uniform heating in the circumferential direction of a portion of the material of the fabricated metal parts 1-1 that is being fed.

It is possible to heat the material of the parts made of metal 1-1 a plurality of times through using at least one preheating element for the material of the fabricated parts of metal 1-1 on the flow-up side of the device. high frequency heating 5 together with the high frequency heating device 5 together with the high frequency heating device 5.

Additionally, through using at least one preheating element for the material of the fabricated metal parts 1-1 on the flow-up side of the high-frequency heating device 5 together with the high-frequency heating device 5, a portion of the material of the parts made of metal 1-1 which is fed may be heated non-uniformly in the circumferential direction. In this way, a portion of the material of the metal fabricated parts 1-1 can be rapidly heated locally by the high frequency heating device 5.

In a third position C which is downstream of the second position B in the feed direction of the material made of metal 1, a cooling device with water 6 performs water cooling of the portion that was heated in the second position B. The cooling device with water 6 cools the material of the parts made of metal 1-1 which was heated in the second position B and which is still in a high temperature state between position B and position C so that its resistance at deformation it is widely reduced.

The water cooling device 6 can be any cooling device through which a desired cooling rate can be obtained and is not limited to a specific type of cooling device. In general, a cooling device with water is used. A cooling device with water cools the material of the parts made of metal 1-1 by spraying cooling water at a predetermined position on the outer peripheral surface of the material of the parts made of metal 1-1.

The cooling water is sprayed at an angle with respect to the direction in which the material of the parts made of metal 1-1 is fed. By varying the distance of the cooling elements from the material of the parts made of metal 1-1 in a direction parallel to a direction perpendicular to an axial direction of the material of the parts made of metal 1-1, the range of the heated region in the axial direction of the material of the fabricated metal parts 1-1 can be adjusted. In this way, the water cooling device 6 rapidly cools the portion of the material of the parts made of metal 1-1 which was heated by the high frequency heating device.

By properly adjusting the cooling start temperature with water through the cooling device with water 6 and the cooling rate, it is possible to temper all or a portion of the chilled portion of the material of the parts made of metal 1-1 . As a result, the strength of all or a portion of the material of the parts made of metal 1-1 can be greatly increased by at least 1500 MPa, for example, or the strength of the portions that are machined as a bore after bending (such as the ball joint support portions and the hub hub installation portions) can be lowered by about 600 MPa, for example, where the ability to go through mechanical work can be guaranteed.

In this way, the portions that are locally heated by the frequency-heating coil 5 and greatly reduced in the resistance to deformation are formed in portions of the material of the parts made of metal 1-1.

A movable roller die 4 is a movable support member for supporting the material of the parts made of metal 1-1 while moving it. A pair of movable rollers 4a, 4a of the movable roller die 4 moves two dimensionally in a plane that is approximately parallel to at least one pair of long sides 12, 13 of the material of the parts made of metal 1-1 in a caudal region down from the third position C in the feeding direction of the material of the parts manufactured with metal 1-1. As a result, a bending moment is applied to the heated portion of the material of the parts made of metal 1-1.

In this way, the movable support elements 4 support the material of the parts made of metal 1-1 which is being fed in a region D downstream of the third position C in the direction of feeding the material of the manufactured parts with metal 1-1, and moves two-dimensionally in a direction that includes at least one feeding direction of the material of the parts made of metal 1-1 to apply a bending moment to the portion of the material of the parts made of metal 1-1 which was heated by a high frequency heating device 14.

Instead of the movable roller die 4 described above, a mandrel mechanism holding the inner surface or the outer surface of the material of the parts made of metal 1-1 can be used as a movable support element. When the mandrel mechanism is employed, it can be supported by an articulated industrial robot, for example.

When the mandrel mechanism is supported by a vertical articulated industrial robot, a mandrel mechanism that is supported by a vertical articulated industrial robot can be used in place of the element. of support 2, a vertical articulated industrial robot can be used as a feeding device 3, and each of the high frequency heating devices 5 and the cooling device with water 6 can be supported by a vertical articulated industrial robot. With this arrangement, it is possible to simplify the structure of the manufacturing apparatus shown in Figure 2.

By moving the movable support element 4 two dimensionally in a plane approximately parallel to at least the pair of long sides 12 and 13 of the material of the fabricated parts of metal 1-1, an arm material 11 can be manufactured having a body lia with a shape shown by the solid lines in Figure 1.

In addition to moving the movable support member 4 upwards and downwards and when moving the high frequency heating device 5 and the cooling device with water 6 in synchrony with this, an arm material 11 having a body can be manufactured. with a shape having a second bent portion 10 and shown by a chain of simple dashes in Figure 1.

In the above explanation, an example is given of a way in which a material is worked in the form of a material of parts made of metal 1-1 having a flat, hollow shape with closed transverse cut 14 which is fed into its longitudinal direction and a support element 2, a high frequency heating device 5 and a water cooling device 6 are fixed in place with respect to the feed direction of the material of the parts made of metal 1-1. However, the present invention is not limited to this mode. Opposite to this mode, a material is worked in the form of a metal parts material manufactured 1-1 can be fixed in place and a supporting element 2, a high frequency heating device 5 and a cooling device with water 6 can be arranged so that it can move in the longitudinal direction of the material of the parts made of metal 1-1.

In this way, the arm material is manufactured 11 described above according to the present invention. Therefore, an arm material 11 according to the present invention is light in weight and compact. An arm material 11 according to the present invention can further be reduced in size and weight and increase in strength by properly adjusting the start temperature and the cooling rate, cooling with water by means of the cooling device with water 6 described above to greatly increase the tensile strength at 1500 MPa or higher, for example. Therefore, an arm material 11 according to the present invention is extremely suitable for use as an upper arm of a double fork suspension 10.

As described above, there is a strong demand to decrease the weight of a higher arm for a car as a countermeasure against global warming. An upper arm that is made of an arm material 11 according to the present invention can be decreased in weight by approximately 10-20% compared to an upper arm that is fabricated by welding a press-worked product made of a steel sheet or by the method described in Patent Document 2. ' As described above, an arm material 11, in accordance with the present invention is tempered by properly adjusting the start temperature of the cooling with water and the rate of cooling through the water cooling device 6. As a result, An arm material according to the present invention develops residual compressive stresses on the external surface of the body Ia to increase its fatigue strength.

As explained while referring to Figure 1, an arm material 11 according to the present invention is manufactured through an extremely simple manufacturing process, so that its production is high and its manufacturing costs are low.

An arm material according to the present invention can be manufactured so that the material for the lower arm is in the same manner as the material described above for an upper arm.

Claims

REI INDICATIONS

1. An arm material for a car suspension characterized in that it has a body made of a material of parts made of metal, where the material of the parts made of metal has a flat, hollow shape, with a closed cross section having a pair of opposite long sides and is formed of a simple element in its longitudinal direction, and the body has at least a first bent portion that is bent in a plane approximately parallel to the pair of the long sides.

2. An arm material for an automobile suspension as set forth in Claim 1 characterized in that, the body has at least a first portion and a second portion in its longitudinal direction, and it has a second portion bent between the first portion and the second portion, where the pair of long sides in the first portion and the pair of long sides in the second portion are in different planes from each other.

3. A method of manufacturing an arm material characterized in that it supports a material of parts made of metal having a flat, hollow shape, with a closed cross section in a first portion while encouraging it relatively in the longitudinal direction, locally heating the material of the parts made of metal that is fed as a second position downstream of the first position in the feed direction of the material of the parts made of metal, in a third position downstream of the second position in the feeding direction of the material of the parts made of metal, cooling the portion of the material of the parts made of metal which was heated in the second position, and imparting a flexion moment to the heated portion of the material of the parts made of metal by changing the position two-dimensional or three-dimensionally, at least in an approximately parallel plane of the pair of long sides of a support element supporting the material of the parts manufactured with metal. In a region downstream of the third position in the feed direction of the metal parts material.